Method and system for delivering biodegradable shelled portions

ABSTRACT

A method of delivering over the air, shelled portions of fluids or granular substances containing effective ingredients, to a target, includes the following stages: selecting a type and a size of the shelled portions containing the required effective ingredients, based on mission parameters and physical data of a scene containing the target; conveying the shelled portions to a delivery point, based on the mission parameters and the physical data; and ballistically delivering the shelled portions towards the target, wherein the shelled portions comprise fluids or granular substances covered by shells that provide the shelled portions a ballistic coefficient that is significantly higher than a ballistic coefficient of similar portions without the shells.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-In-Part of International ApplicationNo. PCT/IL2016/051385, filed Dec. 27, 2016, which claims priority fromIsraeli Patent Application No. 243356, filed Dec. 27, 2015, all of whichare incorporated in their entirety herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of delivery of fluids overthe air and, more particularly, to a method and system for remoteballistic delivery of fluids filled in biodegradable packages usingaerial vehicles.

BACKGROUND OF THE INVENTION

Aerial vehicles are used today in various missions of delivery of fluidsand granular substances from the air. In some cases, delivery from theair is the only option either due to limited access or because of theeffectiveness of the air delivery in covering large areas in a shorttime. Non-limiting examples for such mission include firefighting,fertilizing, cooling nuclear reactors as well as using herbicides andpesticides.

The main challenge in delivering fluids and granular substances, due totheir particle nature, is the tendency of these materials to be greatlyaffected by air resistance. Specifically, large portions of the fluidstransform into an aerosol which drifts by the wind and never reaches thetarget on the ground or above it. The aerosol may also affect the aerialvehicle or people on board it or on the ground. In a case that the fluidcontains harmful ingredients, the aerosol or other buoyant particles cancause health problems or harm the aerial vehicle. Solid granularsubstances suffer from similar limitations and, while they do nottransform into aerosol, their air resistance is sufficiently high suchthat they may lose their ballistic characteristics.

In order to avoid the aforementioned aerosol effect, aerial flightstoday are performed at low altitudes (less than 100 feet above ground).Such a flight profile is very risky, and requires special aircrafts andspecial pilot skills. Because of those high requirements, current aerialmissions can be performed nowadays only at day time and they are stoppedaltogether during the night, or in strong wind and low visibilityconditions, such as smoke, fog or dust.

FIG. 1 is a schematic illustration of an aerial vehicle 10 dischargingfluid 40 from the air towards targets 20 such as trees on the ground 30.Due to the aforementioned air resistance, some portions 50 of the fluidare cut from the main bulk of fluid 40 while other portions of fluid 40transform into aerosol 60. As the aerosol loses its ballistic characterit becomes very difficult, if not impossible, to deliver effectiveamounts of fluid 40 to ground 30 or targets 20. It is noted that theaforementioned problem becomes ever more challenging when air vehicle 10is located higher up in the sky.

After hitting the ground, a material that will not be consumed by fireor be used as a fertilizer may contaminate the ground. Accordingly, anyattempt to encapsulate the fluid inside specially designed packages(e.g., shells) must take into consideration the environmental effect tothese packages. Accordingly, materials such as polymers that can bedisintegrated and/or undergo biodegradation may be considered.

Disintegration involves breaking of at least some of the bonds betweenthe polymer chains due to the exposure of the polymer to UV light (e.g.,UV light coming from the sun), thus causing disintegration of thepolymeric package into small pieces. Such small pieces, if not furtherdecomposed, may remain in garbage yards or shelled portions for years.Composting or underground burial involves complete fragmentation of thepolymer into carbon dioxide, water, inorganic compounds and biomass,leaving no distinguishable or toxic residues.

Composting processes are conducted at closed shelled portions, undercontrolled environment having controlled temperature and humiditylevels, while underground burial requires the use of heavy machinery tocover the plastic residues. The composting process, or the undergrounddegradation process, involves a digestion of the polymer bymicroorganisms into harmful compounds. Such polymers usually containlarge amount of digestible material such as starch acting as the“substrate” for the microorganisms.

Full disintegration and fragmentation of a polymeric package orpolymeric shells into carbon dioxide, water and other harmless compoundsin open air, on the ground is very desirable. Furthermore, when beingburned either accidentally or on-purpose it may be desirable that theproduct of the burning of the polymeric package will not contain anyharmful gases.

BRIEF SUMMARY OF THE INVENTION

Some embodiments of the present invention provide a method of deliveringover the air, shelled portions containing effective ingredients to atarget. The method includes the following stages: selecting a type and asize of the shelled portions containing the required effectiveingredients, based on mission parameters and physical data of a scenecontaining the target; conveying the shelled portions to a deliverypoint, based on the mission parameters and the physical data; andballistically delivering the shelled portions towards the target,wherein the shelled portions comprise fluids or granular substancescovered by biodegradable shells that provide the portions a ballisticcoefficient that is significantly higher than a ballistic coefficient ofsimilar portions without the shells.

The biodegradable shells may include: a first layer comprisingpolysaccharide at a weight % of up to 50% and a polymer matrix, thefirst layer being configured to form a water barrier when in contactwith water; a second layer comprising a polysaccharide at a weight % ofat least 40% and a polymer matrix; and a third layer comprisingpolysaccharide at a weight % of up to 50%, a polymer matrix and anadditive configured to accelerate disintegration of the polymeric shellwhen exposed to natural day light, the third layer being configured toform a water barrier when in contact with water.

The mission parameters may include any of the following: the requiredtype of effective ingredients, the height of the target above sea level,the required height above the target above ground level (AGL), therequired velocity of the aerial vehicle, the footprint and thedistribution at the target, and meteorological effects such as windvelocity and direction around the aerial vehicle at the delivery pointand/or the wind velocity and direction around the target.

Advantageously, some embodiments of the present invention provide asolution to the aforementioned risky flight profile in order to addressthe aerosol effect. Some embodiments of the present invention ensuresafe flight in high altitude for common commercial transport airplanesand further enable performance of the mission at day or at night and inall weather conditions. Furthermore, some embodiments of the presentinvention may provide a solution to the aforementioned contaminationeffect that the shelled portions may have when they hit the ground. Theshelled portions that include the biodegradable shells may undergobiodegradation on the ground responsive to an exposure to free air andnatural day light. Other embodiments of the present invention may berelated to a method of delivering shelled portions.

The method may include: loading the shell portions into an air vehicleand ballistically delivering the shelled portions from the air vehicleto a target. In some embodiments, the shell portions may includeflexible biodegradable shells containing at most 300 gm of fluids. Insome embodiments, the flexible biodegradable shells may be made from amultilayered flexible biodegradable sheet containing polysaccharides ateach layer of the multilayered flexible biodegradable sheet. In someembodiments, ballistically delivering the shelled portions may include:deriving physical data associated with the scene which includes thetarget from one or more sources, wherein at least some of the sourcesare independent of each other, receiving mission parameters includingthe height and speed of the vehicle at the delivery point andballistically delivering the shelled portions to the target usingcalculations based on the physical data and the mission parameters.

These, additional, and/or other aspects and/or advantages of the presentinvention are set forth in the detailed description which follows;possibly inferable from the detailed description; and/or learnable bypractice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more readily understood from the detaileddescription of embodiments thereof made in conjunction with theaccompanying drawings of which:

FIG. 1 is a schematic diagram showing fluid delivery from the airaccording to the existing art;

FIG. 2 is a schematic diagram showing fluid and granular substancesdelivery from the air according to some embodiments of the presentinvention;

FIG. 3 show cross-sectional views of several non-limiting examples forthe shelled portions of the fluid or the granular substance according tosome embodiments of the present invention;

FIG. 4 is a schematic diagram illustrating one aspect according to someembodiments of the present invention;

FIG. 5 is a schematic diagram illustrating one aspect according to someembodiments of the present invention;

FIG. 6 is a high level flowchart illustrating a method according to someembodiments of the present invention;

FIG. 7 is a schematic diagram showing an exemplary embodiment of anairborne dispenser of the shelled portions of fluids and granularsubstances in accordance with some embodiments of the present invention;

FIG. 8 is a schematic diagram showing an exemplary application of someembodiments of the present invention;

FIG. 9 is a schematic drawing illustrating yet another embodiment of theshelled portion in accordance with embodiments of the present invention;

FIG. 10 is a schematic drawing illustrating an aerial vehicle equippedwith a dispenser in accordance with embodiments of the presentinvention;

FIG. 11 is a schematic drawing illustrating a surface vehicle equippedwith a dispenser in accordance with embodiments of the presentinvention;

FIG. 12 is an illustration of various layers in an exemplarybio-degradable polymeric shell according to some embodiments of theinvention;

FIG. 13 is an illustration of a shelled portion according to someembodiments of the invention; and

FIGS. 14A and 14B are photographs of 3 types of shells according to someembodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Prior to the detailed description being set forth, it may be helpful toset forth definitions of certain terms that will be used hereinafter.

The term “shelled portions” as used herein refers to portions of theeffective substance, either in the form of a fluid, powder or granulesthat are packed by a shell, preferably but not necessarily a flexibleshell and/or a flexible biodegradable shell, that is characterized by aballistic coefficient that is significantly higher than the ballisticcoefficient of similar portions of the effective substance or any othermaterial which are not packed by the shells. The shelled portioned aremanufactured so that they resemble ballistic ammunition in size, shapeand weight so as to preserve ballistic properties of the shelledportions which contribute to the repeatability of the aerial delivery oftheses shelled portions. These shelled portions may weigh eachapproximately 100 to 300 grams. The restrictions on the weight stem fromthe fact that proposed shelled portions should not be lethal upon impactwith humans or animals.

Before at least one embodiment of the invention is explained in detail,it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangement of thecomponents set forth in the following description or illustrated in thedrawings. The invention is applicable to other embodiments or of beingpracticed or carried out in various ways. Also, it is to be understoodthat the phraseology and terminology employed herein is for the purposeof description and should not be regarded as limiting.

FIG. 2 is a schematic illustration of an aerial vehicle 10 dischargingloads of shelled portions 100 of either fluids or granular substancesfrom the air towards targets 20 such as trees on the ground 30. Asshown, the shelled portions 100 are selected to be of a size that issufficient to maintain their ballistic character. The actual size oftheses shelled portions is very much a function of the height from whichthese shelled portions are projected, the weather conditions, and thepurpose of the delivery of the fluid or granular substance. It isunderstood that a diameter of 0.5 cm may be reasonable for low altitudemissions (tens of meters), whereas shelled portions having a diameter ofseveral centimeters will be required for higher altitudes (over 100meter). It is noted that the aforementioned values are for demonstrativepurposes only and should not be regarded as limiting the invention.

Consistent with some embodiments of the present invention, the shelledportions of effective ingredients are selected on a per-mission basis tohave the size, weight and packaging material so that they arenon-harmful upon impact with human beings or any objects at the targetare, whenever avoiding harmful impact is a consideration. For example,the packaging material may be a flexible biodegradable polymeric shellmade from a multilayered flexible biodegradable shell (e.g., shell 130illustrated in FIGS. 12 and 13) containing polysaccharides at each layerof the multilayered flexible biodegradable sheet. Put differently, boththe selection of the shelled portion and the ballistic delivering of theshelled portions to a target are carried out in view of avoiding harmfulimpact of the shelled portion in a case of human presence or any objectpresence near or at the target. For example, the shell portions mayinclude flexible biodegradable shells containing at most 300 gm offluids, in order to avoid any harmful impact. In order to protect theenvironment, the materials of the shells may be selected such that theydo not pollute the ground or the air upon falling and breaking at thetarget. In some embodiments, the shells may undergo biodegradation onthe ground responsive to an exposure to free air and natural day light.

Consistent with some embodiments of the present invention, the shelledportions are designed such that a dissemination effect of the fluid orgranular substance is achieved by tearing, opening, or breaking of theshells upon hitting the target or object above the target.

The effective ingredients inside the shelled portion may be determinedand selected on an ad hoc basis. For firefighting, a fire extinguishingmaterial may be used. Pesticides, herbicides and fertilizers may be usedin agricultural applications. The shell should merely keep the fluid orgranular substance in a shape, possibly made of a flexible material,usually but not necessarily a sphere. In some embodiments, the effectiveingredients may include any type fluids that include fire retardantsubstances such as fire-fighting foams and fire-retardant gels. In someembodiments, the effective ingredient may be water (e.g., sweet water,sea water, purified water and the like)

In accordance with some embodiments of the invention, the shells of theshelled portions 100 may be made of bio degradable materials, possiblycompostable materials. By being selected to be biodegradable materials,the shells are able to break down into carbon dioxide, water and biomassonce reaching the target. Advantageously, shells made of biodegradablematerials, may not produce any toxic material and very much like compostshould be able to support plant life. In some embodiments, the shellsmay be made from plant materials such as corn, potato, cellulose, soyand sugar, as disclosed and discussed with respect to FIGS. 12-14. Insome embodiments, the shells are made of materials that break downpossibly but not exclusively through the action of a naturally occurringmicroorganism over a period of several weeks—a period that issubstantially shorter than the decomposing period of biodegradablematerials.

It is, however, to be understood that other materials which are notbiodegradable may be also used for shells, including but not limited topolyester and the like. In some embodiments, the selection of thematerial for the shells is selected so that in the decomposing orbreaking down process, or burning on a fire, neither toxic gases nortoxic fumes are released. The decomposing process may occur on theground and may be accelerated by bacteria on the ground.

FIG. 3 show cross-sectional views of several non-limiting examples forthe shelled portions of the fluid or the granular substance according tosome embodiments of the present invention. Shelled portion 110A includesa shell 130 (e.g., a biodegradable shell) and a homogenous fluid 120that can be selected in accordance with the desired effect at thetarget. Shelled portion 110B includes a shell 130 (e.g., a biodegradableshell) and a granular substance 140 that can be either solid or frozenfluid or ice slurry. In a case of frozen fluid, the shelled portion 11Bmay be used to cool down the target on top of other effects. Forexample, iced granular substance may be tightly packed within a shelland be used to cool a nuclear reactor on the ground. Portion 110C maycontain a portion (with or without a shell) of granular substancepressed together. Two or more ingredients may be used in combination sothat a different effect is achieved at the target (e.g., due to mixing)or prior to hitting the target due to rotational forces. Additionally,at least one of the substances in the packed shell may be arranged togenerate a gaseous substance or foam upon impact at target.

Consistent with some embodiments, shelled portion 110D includes a shell130 (e.g., a biodegradable shell) and a first granular substance 160 puttogether with a second granular substance 170, both of which can beeither solid or frozen fluid. In one embodiment, first granularsubstance 160 may inflate or generate a gaseous substance at the targetthus facilitating the propagation of second granular substance 170.

Consistent with some embodiments, shelled portion 110E includes a shell180 that may be in the form of a frozen fluid and another fluid orgranular substance 190 contained within. The shell may be made by anenvironmental friendly material that disintegrates or evaporated at thetarget. The shell may also be selected for timed application of theeffective ingredient at the target, for example by selecting abiodegradable material for the shell that disintegrated after apredefined time and only then fluid or granular substance 190 is appliedto the target. The shell may also be configured to break or open whilestill in the air prior to the impact with the target so that release ofthe effective ingredients starts well before the impact so that is somecases the impact is with an empty or nearly empty shell.

Consistent with some embodiments, shelled portion 110F includes a shell130 (e.g., a biodegradable shell) and fluid or granular substance 120wherein the shell is shaped as a cube or a prism so that packaging iseasier at the expenses of air resistance.

FIG. 4 is a schematic diagram illustrating one aspect according to someembodiments of the present invention. An aerial vehicle 70 is showndelivering a load of shelled portions 430 in an upward forward directiontowards a target 80. Shelled portions 430 are stored as a payload 420 onaerial vehicle 70 and delivered via a tube 430. It is well understoodthat shelled portions 430 need not necessarily be delivered from anaerial vehicle as long as they are delivered from a certain height andover the air (e.g., from a tower or from a tube on the ground usingpressure).

When dropped on burned trees or vegetation in a wildfire, the shell maybreak up or being opened up at about 30 feet above the flames anddispense the fluid or granular substance in the shells evenly on thetarget.

FIG. 5 is a schematic diagram illustrating one aspect according to someembodiments of the present invention. An aerial vehicle 90 is showndelivering a load of shelled portions 520 using a sleeve 510 configureto move at any direction in order to control the coverage area of loadof shelled portions 520. It is understood that various other methods ofdischarging shelled portions 520 may be used.

FIG. 6 is a high level flowchart illustrating a method according to someembodiments of the present invention. Method 600 takes advantage of theaforementioned shelled portions of various shapes, sizes and contents,and describes a generalized procedure that enables to tailor thespecific shelled portions of substance to the requirements of a specificmission and further based on physical attributes (e.g., physical data)of the scene over the target. Any mission of delivery from the air offluids or granular substance may impose different restrictions such asthe optimal location for the point of delivery, timing considerations aswell as safety constraints. At least some of the stages of method 600may be performed by a computer processor included in a system accordingto some embodiments of the invention. Thus, method 600 may start up withthe stage of deriving physical scene data 610, for example, by thecomputer processor. The physical scene data may be derived from manysources and types of data such as optical, thermal, electromagnetic, andthe like. The method may go on to the stage of obtaining the missionparameters 620, for example, by the computer processor, possibly from auser who plans the mission. These parameters may include, for example:the required type of effective ingredients, the required density of theeffective substance at the target, the elevation over target, therequired time to target, and sometimes minimal distance for deliveringthe substances possibly due to safety reasons. In some embodiments, theeffective ingredients may include any type of liquids that include fireretardant substances such as fire-fighting foams and fire-retardantgels. In some embodiments, the effective ingredient may be water (e.g.,sweet water, sea water, purified water and the like). Then, the methodgoes on to the stage of selecting 620, for example, by the computerprocessor, a type and a size of shelled portions containing the requiredeffective ingredients, based on the mission parameters. The method thengoes on to the stage of conveying 630, for example, by an airbornedispenser controlled by the computer processor, the shelled portions ofthe effective substance to a delivery point, based on the required timeto target and the minimal distance. In a case of delivery using anaerial vehicle, the delivery point is where the aerial vehicledischarges the shelled portions. Finally, the shelled portions areballistically delivered 640 towards the target.

In some embodiments, a method such as method 600 or any other method ofdelivering shelled portions according to some embodiments of theinvention may include ballistically delivering the shelled portions tothe target. The ballistically delivering may include: deriving physicaldata associated with the scene which includes the target from one ormore sources, wherein at least some of the sources may be independent ofeach other. For example, such receiving physical data may include thealtitude, the embossment, plants and buildings covering the target areaand the like. The physical data may be received from maps and/or aerialphotographs stored in databases, aerial photographs received fromcameras of aerial vehicle 90 or any other aerial vehicle and the like.The method may further include using the obtained mission parametersincluding the height and speed of the vehicle at the delivery point toballistically delivering the shelled portions to the target usingcalculations based on the physical data and the mission parameters.

As will be appreciated by one skilled in the art, some of the steps ofmethod 600 may be embodied as a computer implemented method or computerprogram product and may be executed by the computer processor.Accordingly, aspects of some of the steps of method 600 may take theform of an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, micro-code, etc.) or anembodiment combining software and hardware.

The delivery may be in such a way that yields a specified footprint atimpact height over the target. The delivery may be carried out invarious dispensing manners that are selected as to density and form ofdistribution of the shelled portions. The footprint is thus an effectivemetric by which the type of delivery may be carried out.

It is to be understood that the stage of ballistically delivering theshelled portions is carried out naturally once the physical conditions,specifically the size of the shelled portions, are met. It is furtherunderstood that by carefully planning the mission and selecting theappropriate type of shelled portions, the specified targets may bereached in the required timing and the required amount of the effectiveingredients. The selecting and the planning may be optimized inaccordance with the existing variety of the shelled portions and furtherby optimization methods known in the art in different fields.

In accordance with some embodiments of the present invention, thefootprint of the shelled portions at the target is controllable and canbe planned on a per mission basis. This is due to the repeatability ofdelivery of the shelled portions, achieved, as explained above by thehigh ballistic coefficient of the shelled portions. In order to achievethis end, the shelled portions may be homogenous in size, shape andweight. This homogeneity results in a similar ballistic behavior for allshelled portions of a common type. Then, in operation, by selectingmission parameters such as the height and speed of the aerial vehicle atthe delivery point, the footprint of the shelled portions at the targetcan be planned and predicted.

FIG. 7 is a schematic diagram showing an exemplary embodiment of anairborne dispenser of the shelled portions of fluids and granularsubstances in accordance with some embodiments of the present invention.Airborne dispenser 710 is shown on a carriage 720 and further in a crosssection within an airplane 730A and in a top view of an airplane 730B.As illustrated, carriage 720 enables the easy loading of dispenser 710into any aerial vehicle without further adjustments. Dispenser 710 isshaped and configured to be inserted, possibly in modular sections 720so that the volume of the shelled portions is tailored to the plannedmission as well as the carrying capacity of the aerial vehicle. In someembodiments, dispenser 720 may be entered in a matter of few minutes toany standard aircraft and thus convert the standard aircraft into anaircraft that is capable for ballistic delivery of the shelled portions.In order to preserve current delivery methods, dispenser 710 may beconfigured for dual use so that in one configuration the dispenser isoperable to carry on fluids and deliver them in the traditional mannerand in another configuration the dispenser is configured to deliver someshelled portions of the present invention.

Additionally, in some embodiments of the present invention, modularsections 720 of dispenser 710 may each contain a different type ofshelled portions. Dispenser 710 may be further configured to dispense ona single mission, a plurality of types of shelled portions 100 so thatthe selection of the types of shells and the effective substance orfluid may be selected on the fly ad so may be the aforementioned stagesof method 600 discussed above. This feature may further enhanceflexibility of the embodiments of the present invention.

FIG. 8 is a schematic diagram showing an exemplary application of someembodiments of the present invention. The diagram shows a dynamic targeton the ground which includes a first portion 810 and a second portion820. First portion 810 may be a target of a first kind (such as activefire or an oil spill in the ocean), and a second portion 820 may be atarget of a second kind (such as area soon to be caught by the fire orsoon to be contaminated by the oil spill, respectively). In someembodiments of the present invention, it would be possible to tailor theappropriate type of shells and effective substance, to the differenttypes of target as illustrated above, respectively while on a singlemission (shelled portions of type 830 (e.g., made from biodegradableshell) are used for target 810 when airplane is in location 800A whileshelled portions of type 840 (e.g., made from biodegradable shell) areused for target 820 when airplane is in location 800B. This feature isparticularly advantageous when handling a dynamic target being a targetthat changes it size and its nature over a period of time of the orderof a single mission. For example, fire fighting material may be used onthe area already caught by fire 810, while fire retardants may be usedon an area not yet caught by fire 820.

FIG. 9 is a schematic drawing illustrating yet another example of theshelled portion in accordance with some embodiments of the presentinvention. Shelled portion (or pellet) 900 (e.g., made frombiodegradable shell) is shown here in the shape of a hollow ellipsoidwhose shell is punctured with holes such as hole 910. Pellet 900 furtherincludes several fins 912A-912C located on one end of pellet whereineach one of the fins is slightly tilted along the longitudinal axis ofpellet 900 (the tilt angle is exaggerated in the figure for illustrativepurposes). Pellets such as pellet 900 may be effectively and easilyfilled with fluid by grouping together many pellets and submerging themin a container (e.g., within the dispenser apparatus) filled with thefluid containing the effective substance. The fluid then enters throughthe holes. By selecting the holes to be small enough (depending also onthe properties of the fluid), dripping of the fluid is substantiallyavoided when the pellet is in static position. In operation, pellets areballistically discharged from the dispenser into the air. Due to gravityforces and fins 912A-912C, pellet 900 starts rotating around itslongitudinal axis in an increasing angular speed. Beyond a specificthreshold of the angular speed (which can be determined, for example, bythe viscosity of the fluid and the size of the holes), the fluid startsexiting or so-called being sprinkled out of pellet 900 until pellet 900is completely emptied. Pellet 900 can be designed (e.g., size of holes,tilt angle of fins, amount and type of fluid, and the like) incombination with the delivery parameters (e.g., height over target,vehicle velocity and the like) so that pellet 900 is completely emptiedprior to impact with the target so as to minimize the hit at the target.

FIG. 10 is a schematic drawing illustrating an aerial vehicle equippedwith a dispenser in accordance with some embodiments of the presentinvention. Aerial vehicle 1000 can accommodate on its bottom side,approximately near the wings, a conveyer 1010 positioned along itslongitudinal axis. A container 1020 can move freely along conveyer 1010.In order to discharge the aforementioned pellets or other shelledportions discussed herein, container 1020 is being accelerated alongconveyer 1010 from position 1020A to position 1020B where the containeris brought to a sudden and complete stop. A door in the container isthen opened and the shelled portions, or pellets, are forcedballistically out of the container.

FIG. 11 is a schematic drawing illustrating a surface vehicle equippedwith a dispenser in accordance with some embodiments of the presentinvention. Similar to the dispenser described above in regards with theaerial vehicle, the dispenser of surface vehicle 1100 includes aconveyer 1110 that may be tilted to reach a specified angle, and acontainer 1120 that may be moved forward slowly and then brought to acomplete and sudden stop. Conveyer 1010 should be sufficiently long soas to enable a minimal acceleration force applied to container 1020 soas not to affect the shells of the pellets. The exact length of conveyer1010 is determined based on the pellet properties such as the strengthof the shell and the size and number of the holes on it. The shelledportions are thus projected from container 1120 with both vertical andhorizontal velocities that are selected based on the mission and thelocation of the target.

By mere way of example, it is to be understood that many missions may becarried out utilizing embodiments of the present invention. In oneembodiment, the mission may be cooling down of nuclear reactors. In sucha mission there is significant safety distance. Granular ice may be thenused for the cooling. In another embodiment, the mission may be riotcontrol in which the shelled portion may contain non-lethal stinkysubstance, tear causing substance and the like. In firefighting, twotypes may be used as explained above (firefighting and fire retardant).Similarly, in handling oil spills, one material may be used to dissolvethe oil while another substance may be used to hedge the oils spill andreduce its spreading. Many more applications may benefit from advantagesof the embodiments of the present invention.

In some embodiments, shelled portions (e.g., shelled portions 130, 430,520, 830, 840 and 900) made from a biodegradable polymeric shell mayhave to undergo biodegradation on the ground (e.g., on the earth, on thesoil), for example, after hitting the ground. The biodegradation mayoccur responsive to an exposure to free air and natural daylight. Abiodegradable polymeric shell according to embodiments of the inventionor a shelled portion made from such polymeric shell, when left on theground in the free air, may disintegrate into CO₂, water and biomass.The biodegradation may be caused by digestion and/or consumption of thepolymeric shells by microorganisms (e.g., bacteria), funguses or otherorganisms on the ground. The biodegradation process may take arelatively short period of time, for example, 6 months, 12 months, 18months or 24 months.

Biodegradable polymeric shells according to some embodiments of theinvention may include polysaccharides, for example, starch, cellulose,lignin and chitin. The polysaccharides are highly hydrophilic, and thusincluding such compounds in polymeric shells for forming container foraqueous solutions may raise a difficulty. In some embodiments, in orderto accelerate the biodegradation, the polymeric shell may further beconfigured to be disintegrated into small polymeric pieces. UV lightcoming from the sun (during day hours) may cause degradation of thepolymeric chains. This process may be accelerated by addingpro-oxidative additives to the polymer.

Therefore, biodegradable polymeric shell according to some embodimentsof the invention may include two or more layers. A first layer may beconfigured to act as an effective water/liquid barrier for holding thewater or aqueous solution (or other liquids or granular substance), anda second layer may be configured to encourage the biodegradation of theentire polymeric shell.

Advantageously, by using flexible shells and by limiting the weight ofthe shelled portions to 300 grams, the pellets have a dual nature asfollows. For uploading and dispensing the pellets behave like a fluidand can be “poured” easily into the dispenser whenever it needs to beuploaded with several tons over a few minutes. This may be particularlyadvantageous in case the pellets are being produced on site.

Similarly, when letting the pellets bei dispensed from the aerialvehicle at the delivery point, they may be “poured” using onlygravitational force to get them out toward the target. Once in the air,however, the shells provide the fluids within them with a high ballisticcoefficient which characterize solids rather than fluids. The highballistic coefficient guarantees ballistic behaviors which is crucialfor predictability and repeatability of the delivery.

FIG. 12 is an illustration of various layers in an exemplarybio-degradable polymeric shell according to some embodiments of theinvention. A bio-degradable polymeric shell 130 may include a firstlayer 131 and a second layer 132 comprising a polysaccharide. Firstlayer 131 may be configured to form a water barrier that, when incontact with water, may last at least one week. Biodegradable polymericshell 130 may undergo biodegradation on the ground responsive to anexposure to free air and natural day light. Biodegradable polymericshell 130 may be fabricated using any known method of fabricatingmultilayer polymeric shells. Bio-degradable polymeric shell 130 may havea total thickness of at least 30 μm, 40 μm or 50 μm or more. In someembodiments, the total thickness of polymeric shell 130 may be at most100 μm, 150 μm, 200 μm, 300 μm, 500 μm, or 1 mm.

In some embodiments, first layer 131 may include a polymer matrix andfiller. The polymer may include, for example, polyester, polyethylene,or the like and the filler may include polysaccharides, for example,starch, cellulose, lignin, chitin or any combination thereof. In someembodiments, the first layer may include up to 50 weight % ofpolysaccharides, for example, 40%, 30%, 25% and 10%. In someembodiments, the first layer may include at least 10%, 20% or 25%polysaccharides. In some embodiments, first layer 131 may have athickness of at least 5 μm, for example 10 μm, 20 μm, 30 μm.

In some embodiments, the first layer may further include an additiveconfigured to accelerate disintegration of the polymeric shell whenexposed to natural day light. Such an additive may include pro-oxidativeadditives (also known as OXO additives). Exemplary OXO additives mayinclude transition metal stearates that are known to inducefragmentation and degradation in polyolefins in low concentrations(e.g., 5000 PPM and less). Transition metals can switch between twooxidation states resulting in catalytic decomposition to hydroperoxidesthat accelerate the degradation process.

In some embodiments, the first layer may be configured to block watermolecules migration for at least 3 hours, 6 hours, ½ a day, one day, 2days, 5 days, one week or more. For example, when a first side of shell130 comprising first layer 131 is in contact with water, first layer 131may be configured to allow the diffusion of no more than 10% of thewater from the first side to a second side of shell 130, during the atleast 3 hours, 6 hours, ½ a day, one day, 2 days, 5 days, one week ormore. In some embodiments, shell 130 may be in full contact with thewater, such that every external portion of layer 131 may be in contactwith the water. In some embodiments, the water may further apply apressure on polymeric shell 130, and layer 131 may hold the waterbarrier under the applied pressure, as disclosed below with respect toFIG. 13. In some embodiments, the entire water vapor transmission rateof biodegradable polymeric shell 130 may not exceed 50-800 [g/m² day] at37° C. according to ASTM E-96 standard. Examples for shelled portions130, 430, 520, 830, 840 and 900 that includes shell 130 are illustratedin FIGS. 3, 4, 5, 8, 9 and 12.

An exemplary first layer 131 may include polyester with 20 weigh %thermoplastic starch and 0.5 weight % C₅₄H₁₀₅FeO₆(FeSt OXO). Such acomposition may form a water barrier with good impact and strengthproperties. However, due to the relatively low starch content, such alayer may only have a medium biodegradability.

Second layer 132 may include a polymeric matrix and filler. The fillermay include polysaccharides, for example, being at least 40 weight %from the total weight of layer 132. The polysaccharides may be starch,cellulose, lignin, chitin or a combination thereof. The matrix mayinclude polymers, for example, polyesters, polyethylene, or the like.Second layer 132 may be configured to enhance the biodegradation ofshell 130, by providing more nutritious materials for the bacteria,fungus or other microorganisms to consume. The polysaccharides in layer132 may supply the nutritious materials. In some embodiments, firstlayer 132 may have a thickness of at least 20 μm, for example, 40 μm, 60μm or more.

In some embodiments, second layer 132 may further include an additiveconfigured to accelerate disintegration of the polymeric shell whenexposed to natural day light. Such an additive may include pro-oxidativeadditives (also known as OXO additives), as discussed herein.

In some embodiments, adding large amounts of polysaccharides may reducethe mechanical strength of the layer and may further made the layerhighly hydrophilic. Therefore, although having very good biodegradationproperties, second layer 132 may not form by itself a container forholding water based solutions.

In some embodiments, biodegradable shell 130 may further include a thirdlayer 133. Layer 133 may be located at the other side of layer 132 notbeing attached to layer 131 (as illustrated) such that second layer 132is covered by layers 131 and 133 from both sides. Layer 133 may beconfigured to form a water barrier when in contact with water. The waterbarrier may last at least 3 hours, 6 hours, ½ a day, one day, 2 days, 5days, one week or more. Layer 133 may include a polymer matrix andfiller. The polymer may include, for example, polyester, polyethylene,or the like and the filler may include polysaccharides, for example,starch, cellulose, lignin, chitin or any combination thereof. In someembodiments, the first layer may include up to 50 weight % ofpolysaccharides, for example, 40%, 30%, 25% and 10%. In someembodiments, the first layer may include at least 10%, 20% or 25%polysaccharides. In some embodiments, first layer 133 may have athickness of at least 5 μm, for example, 20 μm.

Third layer 133 may be configured to block water molecules from passingthrough polymeric shell 130. For example, when shell 130 is included ina container for holding water, third layer 133 may allow less than 10%of the water held in the container to evaporate from the containerduring one week. The three-layer structure of shell 130 may beconfigured to prevent water and moisture to be in contact withhydrophilic layer 132. In some embodiments, shell 130 may include morethan three layers.

In some embodiments, biodegradable shell 130 may have a tensile strengthof at least 10 MPa, for example, 15 MPa, 20 MPa, 30 MPa or more. In someembodiments, biodegradable shell 130 may have an elongation at break ofat least 100%, 200%, 300%, 400% or more. In some embodiments, firstlayer 131 may provide in addition to being a water barrier also thetensile strength required by the various applications in which polymericshell 130 is to be used. For example, the strength required to holdwater in a container made from shell 130.

In some embodiments, the thicker layer 131 is the stronger shell 130 maybe. Shell 130 having first layer 131 thicker than second layer 132 mayhave higher tensile strength than a shell having first layer 131 thinnerthan second layer 132 or having the same thickness. For example, for thesame total thickness (e.g., 100 μm) shell 130 that includes layersthickness ratios of 60% layer 131 (e.g., 60 μm) and 40% (e.g., 40 μm)layer 132 may be stronger than shell 130 having 50% (e.g., 50 μm) ofeach layer. When adding an additional third layer, such as layer 133having similar or close properties to layer 131, the strength mayfurther increase. Accordingly, a three-layered shell having thefollowing thickness ratios: 30% layer 131, 40% layer 132 and 30% layer133 may have higher tensile strength than a three-layered shell havingthickness ratios: 25% layer 131, 50% layer 132 and 25% layer 133 (forthe same total thickness). In some embodiments, the total thickness ofshell 130 and the thickness ratio between the first, second andoptionally third layer may be determined according to the final requiredtensile strength. For example, the tensile strength required by a water(or other liquid or granular substance) container, such as the shelledportion of FIG. 13.

Reference is now made to FIG. 13 that is an illustration of a shelledportion 110 for holding water based solutions according to someembodiments of the invention. Shelled portion 110 may be made frombiodegradable shell 130. Shelled portion 110 may include sealing 210.Sealing 210 may be strong enough to hold the water or other liquidsinside shelled portion 110 without braking or water evaporation. Shelledportion 110 may be sealed such that no more than 10 weight % of thewater held in the container may evaporate during, one day, 2 days, 5days, one week or more. Shelled portion 110 may have a variety of sizes,each designed to hold different amount of liquids. Shelled portion 110may be designed to hold liquids from 1 milliliter (ml)-100 liter (l) ormore. For example, 10 ml, 50 ml, 100 ml, 200 ml, 500 ml, 1 liter, 5 land 10 l.

In some embodiments, the strength of shelled portion 110 may be suchthat, when a plurality of shelled portions 110 are piled together, forexample, in a tank, both shell 130 and sealing 210 may hold thewater/liquid/granular substance inside each one of the plurality ofshelled portions 110. For example, the strength of shell 130 and sealing210 may be such that shelled portion 110 having a volume of 200 ml.filled with water/liquid/granular substance can endure a compressionpressure applied on the filled shelled portions by an external load ofat least 30 kg, 40 kg, 50 kg or more.

In some embodiments, biodegradable polymeric shell 130 and shelledportion 110 may be configured to undergo a biodegradation on the groundresponsive to an exposure to free air and natural day light, during nomore than 24 months, for example, during no more than 18 months, duringno more than 12 months or during no more than 6 months. Biodegradablepolymeric shell 130 and shelled portion 110 may undergo thebiodegradation to environmentally harmless materials according to atleast one of: ISO 20200, ASTM 6400, ISO 14855 and EN13432. For example,shell 130 and shelled portion 110 left on the ground in the free air mayundergo a biodegradation by bacteria and/or fungus located in the soilto produce CO₂, water and biomass.

In some embodiments, when placed in a fire (either intentionally orunintentionally) shell 130 and shelled portion 110 may be configured tobe burned in the fire without emitting hazardous gasses. As used herein,hazardous gasses may include gases that are harmful to humans wheninhaled or ingested in various quantities. Additionally, hazardousgasses may further include gases that may continue burning or mayexplode. For example, incomplete burning may lead to the emission oftoxic CO, adding various chemicals to the polymeric matrix in at leastone of layers 131, 132 or 133 may result in emitting other harmfulgases. Accordingly, shell 130 and shelled portion 110 may include onlymaterials that can be fully burned to form CO₂ (in the open air) and notemit any other toxic or hazardous gasses.

Experimental Results

Experiments were conducted using biodegradable polymeric shells havingstructure and composition as listed in Table 1:

TABLE 1 Layer Thickness Composition A 15 μm 99.4% biodegradablepolyester with 20% starch, 0.5% photo accelerator (Fe(III)St) + 0.1%slip (erucamide) B 40 μm Biodegradable polyester with high quantity ofstarch (over 5.0%) C 15 μm 99.5% biodegradable polyester with 20%starch, 0.5% photoaccelerator (Fe(III)St)

Tensile Test

Tensile tests were conducted to the biodegradable polymeric shellshaving the structure disclosed in Table 1. The biodegradable polymericshells were tested 7 times in two directions: machine direction (MD—theextrusion direction) and transverse direction (TD). The mean stresses atmaximum load and the stain at the breaking point are given in Table 2:The tests were conducted at a temperature of 23° C., 50% humidity, fullscale load of 0.5 kN and crosshead speed of 500 mm/min

TABLE 2 MD TD Stress at Strain at Stress at Strain at Max load Break Maxload Break (MPa) (%) (MPa) (%) Mean 15.2 652 12.5 591 Standard 0.4 130.2 41 deviation

As can clearly be seen, the mean stress at the maximum load in bothdirections is higher than 10 MPa, and the strain or elongation at thebreaking point is much higher than 100%.

On the Ground Biodegradation Test

The biodegradable polymeric shells having the structure disclosed inTable 1 were tested for biodegradation on the ground responsive to anexposure to free air and natural day light. FIGS. 14A and 14B arephotographs of three types of shells 310-330 taken at day 1 (FIG. 14A)and day 63 (FIG. 14B) after being left on the ground during thesummertime in California. Shells 310 were made from paper, shells 320were made from the same biodegradable polymeric shells disclosed above,and shells 330 were the same shells as shells 320 after being soaked inriver water for 1 hour. As can clearly be seen, all the biodegradablepolymeric shells were disintegrated and at least partially degradedafter 63 days, while the paper shells stayed the same. As expected, whenadding even small amounts of water, the biodegradability of the shellsincreases.

Water Transmission Tests

The water vapor transmission of two samples of the biodegradablepolymeric shells having the structure disclosed in Table 1 was tested.The water vapor transmissions of both samples were 376 g/(m²·day) and327 g/(m²·day). Both samples ha water vapor transmissions of less than380 g/(m²·day).

In the above description, an embodiment is an example or implementationof the invention. The various appearances of “one embodiment”, “anembodiment” or “some embodiments” do not necessarily all refer to thesame embodiments.

Although various features of the invention may be described in thecontext of a single embodiment, the features may also be providedseparately or in any suitable combination. Conversely, although theinvention may be described herein in the context of separate embodimentsfor clarity, the invention may also be implemented in a singleembodiment.

Furthermore, it is to be understood that the invention can be carriedout or practiced in various ways and that the invention can beimplemented in embodiments other than the ones outlined in thedescription above.

The invention is not limited to those diagrams or to the correspondingdescriptions. For example, flow need not move through each illustratedbox or state, or in exactly the same order as illustrated and described.

Meanings of technical and scientific terms used herein are to becommonly understood as by one of ordinary skill in the art to which theinvention belongs, unless otherwise defined.

While the invention has been described with respect to a limited numberof embodiments, these should not be construed as limitations on thescope of the invention, but rather as exemplifications of some of thepreferred embodiments. Other possible variations, modifications, andapplications are also within the scope of the invention.

1. A method of delivering shelled portions, comprising: loading theshell portions into an air vehicle; and ballistically delivering theshelled portions from the air vehicle to a target, wherein the shellportions include flexible biodegradable shells containing at most 300 gmof fluids, and wherein the flexible biodegradable shells are made from amultilayered flexible biodegradable sheet containing polysaccharides ateach layer of the multilayered flexible biodegradable sheet, and whereinballistically delivering the shelled portions comprises: derivingphysical data associated with the scene which includes the target fromone or more sources, wherein at least some of the sources areindependent of each other; receiving mission parameters including theheight and speed of the vehicle at the delivery point; and ballisticallydelivering the shelled portions to the target using calculations basedon the physical data and the mission parameters.
 2. A method ofdelivering shelled portions containing effective ingredients, over theair to a target, the method comprising: loading the required effectiveingredients onto a vehicle in the form of shelled portions selected tohave a type and size based on mission parameters and physical data of ascene containing the target; conveying the shelled portions in thevehicle to a delivery point, based on the mission parameters and thephysical data; and ballistically delivering the shelled portions fromthe vehicle towards the target, wherein the shelled portions comprisethe effective ingredients covered by flexible biodegradable shells, andwherein each of the biodegradable shells comprises: a first layercomprising polysaccharide at a weight % of up to 50% and a polymermatrix, the first layer being configured to form a water barrier when incontact with water; a second layer comprising a polysaccharide at aweight % of at least 40% and a polymer matrix; and a third layercomprising polysaccharide at a weight % of up to 50%, a polymer matrixand an additive configured to accelerate disintegration of the polymericshell when exposed to natural day light, the third layer beingconfigured to form a water barrier when in contact with water.
 3. Themethod according to claim 2, further comprising deriving physical dataassociated with the scene which includes the target from one or moresources, wherein at least some of the sources are independent of eachother.
 4. The method according to claim 2, wherein the shelled portionsare homogeneous in size and weight.
 5. The method according to claim 4,wherein the vehicle is an aerial vehicle, the method further comprisingcontrolling the footprint of the shelled portions at the target byselecting mission parameters including the height and speed of thevehicle at the delivery point.
 6. The method according to claim 2,further comprising targeting the delivering of the shelled portionstowards the target using optical targeting means that predicts impactarea for the shelled portions at any given time.
 7. The method accordingto claim 2, wherein the biodegradable shell has a water vaportransmission rate of the bio-degradable polymeric shell is between50-800 [g/m² day] at 37° C. according to ASTM E-96.
 8. The methodaccording to claim 2, wherein the shelled portions comprise a shell thatis configured to break prior to impact with the target so as to releaseat least some of the effective ingredients prior to the impact with thetarget.
 9. The method according to claim 2, wherein the shelled portionscontain two or more substances that are arranged to interact uponhitting the target or prior to the hitting due to rotational forces. 10.The method according to claim 2, wherein the shelled portions containtwo or more substances, and wherein one of the two or more substances isarranged to generate a gaseous substance or foam upon impact at targetor prior to the impact.
 11. The method according to claim 2, wherein theballistically delivering is carried out by an aerial vehicle.
 12. Themethod according to claim 11, wherein different types of shelledportions are loaded onto the vehicle, wherein the selecting is carriedout during flight of the aerial vehicle.
 13. The method according toclaim 11, wherein the loading is performed using a dispenser that isarranged to fit into a plurality of types of aerial vehicles.
 14. Themethod according to claim 2, wherein ballistically delivering theshelled portions is carried out using a dispenser that comprises aconveyer and a container that contains the shelled portions, wherein thedispenser is configured to accelerate the container along the conveyerand then bring the container to a complete and sudden stop so as toforce the shelled portions ballistically out of the container.
 15. Themethod according to claim 2, wherein each one of the shelled portionsincludes holes going through the shell and tilted fins located at oneend of the shell designed such that during the ballistic delivery,wherein the shelled portions rotate around their longitudinal axis at anincreasing angular speed which results in the fluid exiting the shelledportion.
 16. A system for delivering over the air, shelled portions offluids or granular substances containing effective ingredients to atarget, the system comprising: a vehicle configured to convey theshelled portions to a delivery point based on mission parameters andphysical data; and a dispenser configured to ballistically deliver theshelled portions towards the target, wherein the shelled portionscomprise fluids or granular substances covered by biodegradable shellsthat provide the shelled portions a ballistic coefficient that issignificantly higher than a ballistic coefficient of similar portionswithout the shells, and wherein each of the biodegradable shellscomprises: a first layer comprising polysaccharide at a weight % of upto 50% and a polymer matrix, the first layer being configured to form awater barrier when in contact with water; a second layer comprising apolysaccharide at a weight % of at least 40% and a polymer matrix; and athird layer comprising polysaccharide at a weight % of up to 50%, apolymer matrix and an additive configured to accelerate disintegrationof the polymeric shell when exposed to natural day light, the thirdlayer being configured to form a water barrier when in contact withwater.
 17. The system according to claim 16, further comprising acomputer processor configured to derive the physical data associatedwith a scene which includes the target.
 18. The system according toclaim 17, wherein the computer processor is further configured to obtainmission parameters containing at least one of: a required type ofeffective ingredients, the required density of the effective ingredientsat the target, and a desired distribution footprint of the shelledportions at the target.
 19. The system according to claim 16, furthercomprising means for optical targeting the delivering of the shelledportions towards the target so that the impact area for the shelledportions at any given time is predicted.
 20. The system according toclaim 16, wherein the biodegradable shell has water vapor transmissionrate of the bio-degradable polymeric shell is between 50-800 [g/m² day]at 37° C. according to ASTM E-96.
 21. The system according to claim 16,wherein the shelled portions comprise a shell that is configured tobreak or open prior to impact with the target so as to release at leastsome of the effective ingredients prior to the impact with the target.